ESPN NFL

MIAMI -- The Miami Dolphins' offense came off the field following a long touchdown drive, and waiting to offer congratulatory handshakes were Reggie Bush, Chad Henne and Brandon Marshall.

While starters watched, the Dolphins won a battle of backups Thursday night by beating the Dallas Cowboys 17-3 in the final exhibition game for both teams.

Reluctant to risk injuries so close to the start of the regular season, the Cowboys designated 31 of their 80 players as inactive, while the Dolphins had 21 inactive players. Three starters were active for each team.

Larry Johnson scored on a 22-yard touchdown run for Miami, and backup quarterback Matt Moore threw for another score.

Dolphins coach Tony Sparano decided to rest many of his players after holding two physical practices this week. Instead, he used the game to assess players battling for roster spots.

"To see some of the guys you have questions about and want to see play a bunch was helpful," he said.

One of those players was Johnson, a two-time Pro Bowl selection who signed with the Dolphins last week after sitting out most of last season. He rushed for 39 yards on 10 carries and scored the game's first points.

"It was good to get him into the mix," Sparano said. "The guy knows how to score touchdowns."

Actually, Johnson hasn't scored a regular-season TD since 2008 with Kansas City. Repeated missteps and two suspensions in his final 12 months with the Chiefs derailed his career.

"It's not necessarily that my talent has gone down," Johnson said. "It's more my off-the-field issues and problems have always overshadowed my ability. I shot myself in the foot. For me it's being able to play catch-up and doing it the right way."

Moore, another Miami newcomer, went 9-for-11 for 142 yards, including an 18-yard touchdown pass to third-string tight end Jeron Mastrud.

"I liked what Matt did," Sparano said. "We were simple and basic, but Matt did a good job."

Dallas third-string quarterback Stephen McGee went 21-for-25 for 233 yards but couldn't get his team into the end zone. The Cowboys' only points came on a 20-yard field goal by David Buehler, who is battling to keep his job.

Running back DeMarco Murray, competing for a backup role behind Felix Jones, carried 10 times for 32 yards and caught four passes for 64 yards.

"I feel great," Murray said. "I just want to help the team however I can."

Murray, a third-round draft pick, made his practice debut last week after being sidelined by a hamstring injury. He's listed as a third-stringer along with Phillip Tanner, who rushed for 28 yards in six carries, and both might make the team.

"We'll talk about that over the next couple of days," coach Jason Garrett said. "Both of those guys did a good job tonight."

The only Dolphins starters active were receiver Brian Hartline, linebacker Koa Misi and safety Chris Clemons. Cowboys active starters were fullback Chris Gronkowski, top draft pick Tyron Smith and rookie guard Bill Nagy.

With roster cuts looming this weekend, about half the players who saw action will likely be released.

Dallas (2-2) plays its regular-season opener Sept. 11 against the New York Jets.

"We're fired up and ready to go," Cowboys receiver Dez Bryant said after taking the night off.

Miami (3-1) opens Sept. 12 against New England. Like Bryant, Sparano is sounding confident.

"There's a different buzz on this team right now," the coach said. "There's a good vibe, which is why I think this team is going to win."

Moore, slated to back up Henne this season, started the game and led touchdown drives of 79 and 59 yards. His completions included a deep pass to speedy rookie Clyde Gates for a 42-yard gain that set up a TD.

Dan Carpenter kicked a 50-yard field goal for Miami.

On the Cowboys' first play, Murray took a short pass from McGee and turned it into a 48-yard gain. McGee later led Dallas on a 17-play drive that took nearly 9 minutes and ended with Buehler's field goal.

Game notes

Undrafted rookie receiver Raymond Radway, who had a chance to make the Cowboys' roster, broke his left leg trying to catch a pass with 3 seconds left. ... Miami veteran Will Allen, battling for a roster spot, leaped to break up a pass in the end zone by McGee that was intercepted by Tyrone Culver. ... The Dolphins committed only two penalties for 15 yards. ... The small crowd included at least one celebrity: singer Cee Lo Green.